We propose to continue studies leading to a new and general method for constructing cyclohexane rings for natural products synthesis. We hope to be able to define the scope and limits of the method as well as to complete several syntheses of naturally occurring molecules currently in progress. BIBLIOGRAPHIC REFERENCE: Photoannelations with alpha-Formyl Ketones. A Facile Synthesis of the cis-9, 10-Dimethyldecalin Ring System of the Valerane Sesquiterpenes. S.W. Baldwin and R.W. Gawley, Tetrahedron Lett., 3969 (1975).